The present invention is generally directed to a turnover device for web-shaped recording media arranged inside an electrographic printer or copier.
With respect to modern electrographic printer systems, highly economical usage and broad flexibility are increasingly demanded by customers. Both the effective utilization of printing materials as well as the flexible design of the print information thereby play an important part.
Continuous-processing (fan-fold) electrographic printing systems capable of one-sided printing on a web-shaped recording medium have prevailed in the marketplace where high availability of the apparatus given large printing volume and a broad spectrum of printing materials are required. These printer systems, however, are disadvantageous in that they cannot be switched between single-sided (simplex) and double-sided (duplex) printing. This leads to an unfavorable economic situation for the user and also runs contrary to contemporary ecological demands to efficiently utilize raw materials. Many customer-associated demands that necessarily require double-sided printing (brochures, books, etc.) can thus not be satisfied, particularly since electrographic high-performance printers are especially efficient when operated without interruption.
For producing multi-color and backside printing with electrographic printer devices that process continuous stock, EP-B1-01 54 695 discloses that two continuous stock printers operated following one another, whereby the paper printed in the first printer is turned over and is subsequently printed on the second side in the second printer. The outlay is substantial due to the requirement of a second printer.
The reference IBM Technical Disclosure Bulletin, Vol. 22, No. 6, Nov. 1979, pp. 2465-2466 also discloses an electrophotographic printer device for printing web-shaped recording media with which it is possible to print the recording medium on both sides. To this end, the recording medium is taken down from a supply stack, is supplied to a transfer printing station and is provided with toner images on one side. After being fixed, the recording medium is turned over with the assistance of a turning mechanism composed of deflection rods and is resupplied to the transfer printing station. After printing the backside of the recording medium with toner images, fixing is again carried out in the fixing station.
This reference basically discloses duplex printing with continuous stock media. The proposal, however, never led to a product. Further, this electrographic printer device is suited only for both-sided printing of the recording medium. A change in operating modes is not provided. The turnover means composed of deflection rods that is employed requires manual threading of the recording medium. Moreover, the nature of the arrangement of the deflection rods requires a great deal of integration space.
It is therefore an object of the present invention to provide a turnover means for web-shaped recording media that enables an automatic threading of the recording medium.
Another object of the invention is to fashion the turnover means such that it can be arranged integrated in user-friendly fashion in an electrographic printer means with which single-sided and both-sided printing of a web-shaped recording medium is possible.